diff --git a/lib_node_shell/peer_validator.ml b/lib_node_shell/peer_validator.ml
index 0f8015d09..e66329e6c 100644
--- a/lib_node_shell/peer_validator.ml
+++ b/lib_node_shell/peer_validator.ml
@@ -191,12 +191,13 @@ let rec worker_loop pv =
   end >>= function
   | Ok () ->
       worker_loop pv
-  | Error (( Unknown_ancestor
+  | Error ((( Unknown_ancestor
            | Block_locator.Invalid_locator _
-           | Block_validator.Invalid_block _ ) :: _) ->
+           | Block_validator.Invalid_block _ ) :: _) as errors ) ->
       (* TODO ban the peer_id... *)
       lwt_log_info "Terminating the validation worker for peer %a (kickban)."
         P2p.Peer_id.pp_short pv.peer_id >>= fun () ->
+      lwt_debug "%a" Error_monad.pp_print_error errors >>= fun () ->
       Lwt_canceler.cancel pv.canceler >>= fun () ->
       Lwt.return_unit
   | Error [Block_validator.Unavailable_protocol { protocol } ] -> begin